docs/historical-manpages: add DEP5 copyright file

Add debian copyright file for historical manpages. Copyright was
mentioned in the manpage comments, but wasn't otherwise visible.

While at it, make files ending up at .gz actually gzip'ed.

Signed-off-by: Manos Pitsidianakis <manos@pitsidianak.is>

meli/docs/historical-manpages/copyright

@@ -0,0 +1,42 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Comment: This directory contains various manual pages that may be of use to meli users.
+
+Files: mailaddr.7.gz
+Comment: Sourced from debian manpages package.
+Copyright: Copyright (c) 1983, 1987 The Regents of the University of California.
+License: 6.5 (Berkeley) 2/14/89
+ Redistribution and use in source and binary forms are permitted
+ provided that the above copyright notice and this paragraph are
+ duplicated in all such forms and that any documentation,
+ advertising materials, and other materials related to such
+ distribution and use acknowledge that the software was developed
+ by the University of California, Berkeley.  The name of the
+ University may not be used to endorse or promote products derived
+ from this software without specific prior written permission.
+ THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+Files: maildir.5.en.gz
+Comment: Sourced from debian maildrop package.
+Copyright: Copyright 1998 - 2007 Double Precision, Inc.
+License: GPLv3 with OpenSSL linking extension
+ This software is released under the GPL, version 3 (see COPYING.GPL).
+ Additionally, compiling, linking, and/or using the OpenSSL toolkit in
+ conjunction with this software is allowed.
+
+Files: mbox.5.en.gz
+Comment: Sourced from debian mutt package.
+Copyright: Copyright (C) 2000 Thomas Roessler <roessler@does-not-exist.org>
+License: public-domain
+ This document is in the public domain and may be distributed and
+ changed arbitrarily.
+
+Files: mbox.5qmail.en.gz
+Comment: Sourced from (now obsolete) debian qmail package.
+Copyright: D. J. Bernstein
+License:  From http://cr.yp.to/qmail/dist.html
+ I hereby place the qmail package (in particular, qmail-1.03.tar.gz,
+ with MD5 checksum 622f65f982e380dbe86e6574f3abcb7c) into the public
+ domain.  You are free to modify the package, distribute modified
+ versions, etc.